Throttling device



Jan. 15, 1952 F. AAGAARD 2,582,917

THROTTLING DEvcB F11ed Apri1 8 1947 2 SHEETS-SHEET 1 ATTC)RN EY advantages of the pfiof devioes.

Pafenfed Jan. 15, 1952 UNTEo STATES PATENT .o FcE TEBoTTLING DEvIoE Erfotjof Aogoord, Iohvvoy, ff. J ossfgnor fo Anlerioon cyononio conpony, Now fofk, 1To f., o cofpofotion of ffoine This invention relates to a contTo1 valve for varying the f1ow of fiuid thfough a oonduit.

There are nuInerous inStanceS Where it is neoessary to oontro1 the fate of a oontinuouS flow of uid thfough a oonduit. In many caSeS this iS effected nlanually and in othef caSeS auto Inatioally, suoh as eleotro-pneunlatio oontrolS. vvith ofdinafy nonooffoSive, olean f111idS the oon tfo1 valve pfobleIn is not Sefious ond any ofdi nafy type of thrott1ing valve may be used.` The problen1, hovvevef, beoones sefious Whefe the fluid iS ooffoSive and vvhefe it is not olean but Inay oontain suspended SolidS. In Suoh oaJseS aJ sefious problefn is presented When tho flovv has to be oon tfoHed to a sma11 volulne. MoSt oommonly the pfoblem afises with the contTo1 of flow of liquidS, thefefore, the fen1ainder of the Speoification vvi11 dea1 vvith 1iquid f1ovv contro1 devices.

The ooffosive effeot neceSSitateS the use of o()1 Tosion fesiStanf valve ffajteI'iaJ1 vvf1ich often has unsuitable phySioa1 pfopeftieS, Suoh aS hard rubber valveS and the like and Whioh uSually iS nluch fflofe expensive. The pfobleIn of SuSpended solids vvith slTla11 f1oWs is even f1ofe sefious beoauSe when a sn1a11 passagevvay iS pfovided by the valve, vVhich is necesSa1'y when a Sman oW is desifed, there is aJ Sefious tendenoy to ologging When iarge partioleS afe preSent in the liq11id. A Sinlilar pfoblen1 is enoountefed vvith Sn1o11 f1ows vvhen gas bubbles are present of With liqllidS oontoining gummy subStances.

It is a oonlpafatively siInple pTobleIn in the labofatofy to handle oorrosive liquidS- A oof 1'osion fesistant, flexible tubing, such aS rubber of plaStio, f1ay be oontroned by a pinoh oook. This wofkS Wo11 With ooffosive nlatefiaL but pfesentS aJn even Inore SefiouS o1ogging probleIn with SIna11 fiows if thefe iS present any conSidefable quantity of suspended Solids in the liquid. close Supef vision and Inanua1 oontro1 Inakes it possible to opefate but vvhen auton1atio oontfol iS used, paf tioularly when the va1ve of thfott1ing dovice iS in an inacoesSible poSition, ologging is aJ very SefiouS nlatfer and fnay oause daInaging-interfuptionS.

The pfesent invention overooInes oJ11 of the diS sSentiany it oonSiStS of a helioal ooi1 of flexible ooffoSion re Sistant tubing around a So1id nlandriL refeTably positioned betWeen two plates. Movement of one of the plateS cofnpreSSeS eooh tufn of t11bing be tween the plates and the InandfiL plurality of constrictions result and if a sufcient number of tufns of tllbing is uSed no single oonStTicfion iS sIfIa11 enough to preSent a c1ogging problen1 and the large numher of oonstfiotionS iI1 series 2 vi11 introduoe sunfoient thfottling eifect so that o sn1a11 and accufately contro11ed oow fnay be fnaintained.

The pfesent invention solveS cofnpletely the o1ogging pfoblen1 eve fo1' relatively Sn1a11 fiovvs ond it is also an exoenent Solution foI' the oof fosion pfoblem beoauSe any kind of exib1e tubing may be en1ployed and a Suitable corfoSion re sistant Inotefial nloy be chosen beoause thefe iS no pfobleIn of other requifeh1entS of Inechanioal strength whioh ariseSwhen corroSion resistant valveS afe employed. lf'11e tubing is oonStrioted on1y a little at eaoh po1t vvhioh inofeaseS itS 1ife beouSe it is not fiexed of So shafp an angle aS Would be neoeSSary if a Single oonstriotion were relied on. fhe life of the tubing is gfeatly lengthened and the feliability inoreaSed Whioh is of gfeat ifnportanoe in the case of thfottling de vices of valves Which are used in aoceSSible 1oca tions. Another advantage lies in the fact the only paft of the IneohaniSn1 Whioh iS Subjeot to vvear of to oontact vvith ooffosive liq11ids oan be feadny feplaced and the oost of the Sma11 amount of noxible tubing iS neg1igible,

While the present invention is bToady oon cefned vvith thfottling devioeS in vvhich a helix of nexible tubing on a fnandril is ooInpfesSed betWeen one or mofe plates regardless of the meohanoa1 Strnoture employed pfefer to use devioes in vvhich the fnoveable plafe of p1ates Slide in gujdes So that the plates afe pafalle1 to the axiS of the nlandfi1 and a11 tufnS of the helix of the 1iexible tubing afe equany oompfeSSed. This pfevents exoeSSive oonstriotion at one point ond perInits minimum oW With maxnum feliability against ologging. A1so the oontro1 iS II1ofe SInooth and n1ofe unifoffn if the plateS fefTlojif1 pafa11eL The refefence to plates Should not be oonsidered aS lifffiting tho invention to plateS With f1at sides olthough if iS an odvantage of the pfeSent inven tion that vefy siTnple oonStriotions using fiat plates in conventiona1 ffaTneworks n1aJ r be en1 p1oyed, Whe1'e it is deSired to effeot aJ maximum thfottling With a minimum length of helix the plateS Inay be ourved So that al lafgef area of eaoh turn of the helioa1 tubing iS oonStfioted. t iS purely o lTatte1' of econon1ics and 1nechanioa1 oonvenience vvhethe1' flat plateS or oufved plateS afe used because, of ooufSe, the SaIne degfee of contro1 oan alvvayS be obtained With at plateS if the nuInbef of tuTns of the helix iS Suiciently gfeat. IIovVevef, in oeftaif1 oaSeS Whefe fnaxifnun1 oofnpaotness iS an in1poftant faotof ourved plates 11ow o11ce haS been nade the1ooknut16 1S tight ened and the pneunlatic controller is tl1en th1 ovvn into operation,

fhe contronef is Set for a deSired steady f1ow of liq11id and opefates in oonventiona1 Tnanner to inofeaSe the aif pfeSSure in the tube T unti1 the plate 6 has n1oved a Sun1c1ent distanoe to con Strict the tufns of the helix 6 untn the flow of liquid iS feduoed to the pTedeterInined volume for which the oontro11eI is set. 1 ron1 theTe on the oontro11er operates in oonventional lTlanner, an increaSe in 1iow feS111ting 111 an i11cfease of air pfessure fro1n the contro11er to the tube 1 unti1 the plate oonstriots the helix 6 Sufoient1y to reduce the 11OW to the predetefmined gore. Cofresponding1y a reduction in 11ow results in fe duced ai1, pTeSSure fron1 the oontTo11ef Whioh permitS the plate 3 to fiSe and feduoe the oonStfic tion of the helix 6 unti1 nofIna1 f1ov is again feached.

The pneun1atic f1()W contfo11er is not ShoWn aS any conventiona1 pneuInatic nOW contTo11er Inay be uSed and the present invention iS not liInited to the use of any partioulaf contfoller deSign. SiInilarly the contro11er 11oid is not 1inited to air of another gas. LiquidS are equa11y usefu1 as, of couTSe, the f1exib1e tube 1 1espondS to ohanges in 1iquid preSSuTe in preciSely the SaIT1e way as it doeS to ohngeS 111 aiT pressure.

vvhefe Wide f1uctuationS in 1iquid pfeSSufe afe enoountered a con1penSated throttle valve iS de Sifable and Such a valve is i1111Stfated in igS and 5- This valve 111ollldeS the frafneWofk, stad tionaTy lateS Inoveable plates, adjusting sorew, helix and n1andfi1 of the unoofnpensated Inodi- 11oation shown in Pigs- 1 to 3 and aooording1y theSe partS bear the San1e feferenoe nunlefalS. conlpensation iS eIfected by Ineans of a second olosed end f1exible tube between plates 3 and 4 Which is Shown aS nlounted in the centeT of a U Shaped olosed end nexible tube !2 connected to the pneuInatic f1OW controller. This u t11be feplaoes the straight tube 1 of 1 igs. 1 to 3. The open end of the co1npenSating t11be is oonneoted through pipe l3 to the tub1g 6 at the point of liq11id inlet, the direotion of liquid f1ow through the helix being shown by arTowS,

The valve is adjuSted With nornla1 1iquid pres- Sufe foI n1X11nuIn 11ovv exaotly as desc1fbed in oonneotion With the unoonpenSted valve of 1 'igs. 1 to 3. l0W is then controlled to the va1oe set on the pneunlatic f1ow contro11er by the air pfessure in the flexib1e U t11be 12. T11e position of the moveable plate 3 iS thuS detefInined by the Su1n of the forceS exefted by the con1penSating tube and oontro11eT tube 12. Any increase in f1uid pfesSufe at the inlet to the he1ix feSults in inofeased pressure in the expanSible contfoller a11 t11be vv11ich vvi11 Cause the plate 3 to fnove and Wi11 fufther TeStrict the helix 6 thos coInpenSating, at leaSt paTtially, for the inofease in liquid pTessufe. The degfee of oofnpenSation Wi11 depend, of course, of the relative sizes of the f1ex iblo tubes and l2. sufoient co1pensation is provided to neutfaliZe a lafge poftion of the ef fect of preSSure f111ot11ations so that the pneu 1I19tio f1ovv contro11ef only opefateS on the S1na11 fesidua1 f1ow changes aJIld those Which 1esult of ohnges in f10W oonditionS beyond the throttle va1ve.

I olai1n= l 1. A pneumaticany cont1o11e.d thTott1ing de vice for fluidS oo1npfising in oofnbination a In111ti tufn he1i) of 11eXible tubing on a figid nandIiL through Which tubing the f111id to be thTottled 11ovvS, gL1ides at right ang1es to the axis of the TnondriL a rigid bottoIn plate faStened to one end of the guides and 111 oontact With the 11elix, al Second plate in oontaot vvith the helix on fhe side opposite the bottom plate and out of contact With the guideS but oopable of n1oven1ent at right angles to the fnandril axis, a third plate spaoed fro1n the Second plate and s1idable 1on itudinally on the guides, a f1exib1e tube cloSed at one end adapted to be oonnected to a SOuToe of varying gas pfeSSufe betWeen the Seoond and thifd plateS and 111eans for adjuSting the position of the third 1ate on the guideS the nlandfil being ffeely Inoveable in a difection pafanel to the guideS,

2. f1 pfessnfe coInpenSating thfottling device aocofding to o1aiIn 1 in Whioh an a.dditiona1c1osed end 11exible tube iS Inounted betvveen the plates, the ope11 end of which is oonnected fo a So111ce of f1uid pressure pToportiona1 to the inlet pres Sufe on the1iquid.

3. 11 pfeSsure oon1pensating thfottling device aocofding to olai111 1 in v/hioh an additiona1 closed end 11exib1e tube iS lnounted betvveen the plates, the open end of which is connected to the iI11o6 end of the Inulti-turn helix.

A thfottHng devioe fo1- 11uid f1ow ooInprising in coInbination a Inu1titurn he1ix of f1ex ib1e tubing afound a rig1d Inandri1 thfoogh Whioh the f1uid to be thfott1eo flowS, g11ides at right angles to the aXis of t11e n1andriL a rigid p1ate faStened to one end of the guideS and in contaot vith the he1i, a Second p1ate in oontact With the helix on the side ooposite the figid plate and Inovable at right angles to the Inandri1 axis and n1eanS for n1oVing said 1novab1e p1ate to vafy the spacing betWeen Tigid plate and Inovable p1ate Whereby eaoh tuTn of the helix iS ooInpfeSSed at al plurality of pointS.

BEEEBENoES oITED The f011ovving feferenoes are of feoord in the 1 lle of th1S patent= UNITBD STATBS PATNTs 5d NnInbeI Nan1e lDaite 597,3 T11oInas Jan. 18, 1898 1 12o,oo2 vvalquist Deo. 8 191 1 28,65 yn 1Tov 12, 1918 1,983 213 Bfady Deo. 4, 193 2,069 261 1o111 1et eb, 2, 1937 2,422,921 1`Tier June 24, 19 17 2 192,14=9 ffeuver 1ec. 27, 1949 65 NuInber country 1)ate 202 70 Gfeat Bfitai11 of 1923 

